The present invention relates to an electric or electrochemical cell having a zinc negative electrode, a positive electrode and a saline electrolyte containing a corrosion inhibitor to inhibit corrosion of the zinc electrode by the electrolyte.
The problem of the storage of electric cells for a reasonable time arises more particularly under severe climatic conditions, such as heat and dampness conditions in tropical regions. To avoid cell deterioration due to corrosion of the zinc by the electrolyte, it becomes necessary to insert into the electrolyte compartment of dry electric cells of a product that will inhibit the corrosion of zinc by the electrolyte which latter is usually a paste.
In the past, inhibitor products such as petroleum or mineral oils or animal oils have been recommended for such corrosion preventive purposes, as has the use of chromates or chromic acid. Most of these products tested up to the present time either have proved to be ineffective or else found to have a detrimental influence on the discharge of the electric cell.
The present invention makes it possible to overcome the disadvantages of the known art referred to above.
Objects of the present invention are the provision of an electric cell having a zinc negative electrode, a positive electrode and a saline electrolyte, characterized in that the electrolyte contains as the corrosion inhibitor ascorbic acid in a proportion greater than 200 mg/l.
Preferably, the ascorbic acid concentration in the saline electrolyte is comprised between 700 and 900 mg/l.
Other objects and features of the present invention are the provision of electric so-called dry cells containing a corrosion inhibitor which renders it possible to store such cells for long periods in adverse environments such as those of heat and dampness as may be encountered in tropical regions by inhibiting attack on and perforation of the zinc electrode by the electrolyte.
Further objects and features of the invention will become apparent from the following detailed description.